To assess the role of Ras in adult hematopoiesis and in BCR/ABL leukemogenesis, and to assess the importance of Ras as a therapeutic target, we examined the effect of N17 H-Ras mutant in bone marrow reconstitution and in the induction of CML-like MPD by BCR/ABL in mice. Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.